Low-cost tool set for removing brazed fittings

Set includes crimping tool and pull tube. Crimping tool is modified vise-grip pliers which has special jaws designed to crimp fittings. Pull tube has single thread on each end. Tube can be used once on each end before discarding

On the Emergent Dynamics of Fermions in Curved Spacetime

Relativistic spin-1/2 particles in curved spacetime are naturally described by Dirac theory, which is a dynamical and Lorentz-invariant field theory. In this work, we propose a non-dynamical fermion theory in 3+1 dimensions dubbed spinor topological field theory, built in terms of a spinor field and a Cartan connection related to de Sitter group. We show that our model gives rise to the Dirac theory in curved spacetime when the local de Sitter gauge invariance of the model breaks down to the Lorentz gauge invariance, providing also a geometric origin to the fermion mass. Finally, we show that other gauge fields and suitable four-fermion interactions can be included in a straightforward way.Comment: 3 pages, published versio

Tubing cutter

Replacement of opposing smooth rollers with appropriately grooved rollers in manual tubing cutter allows smooth severance of tubing of different diameters and eliminates raised lip around cut end

From topological to topologically massive gravity through the gauge principle

It is well known that three-dimensional Einstein's gravity without matter is topological, i.e. it does not have local propagating degrees of freedom. The main result of this work is to show that dynamics in the gravitational sector can be induced by employing the gauge principle on the matter sector. This is described by a non-dynamical fermion model that supports a global gauge symmetry. By gauging this symmetry, a vector-spinor field is added to the original action to preserve the local gauge invariance. By integrating out this spin-3/2 field, we obtain a gravitational Chern-Simons term that gives rise to local propagating degrees of freedom in the gravitational sector. This is defined, after the gauging, by topologically massive gravity.Comment: 5 pages, this essay has received an Honorable Mention from the Gravity Research Foundation - 2019 Awards for Essays on Gravitatio

Ideas, Interests, and Institutional Change: the European Commission Debates the Delegation Problem

The forthcoming Commission White Paper on Governance devotes a good deal of attention to the possibility of delegating rule-making powers to independent European agencies. The extensive debate stimulated by thepreparation of this document has revealed deep differences of opinion. The orthodox doctrine, stubbornlydefended by the Legal Service, holds that such delegation would upset the balance of power among ECinstitutions, reduce the Commission’s ability to fulfill its duties under the treaties, and ultimately undermine theconstitutional foundations of the Community. By contrast, the reformers maintain that the received view ondelegation is by now completely outdated, and that the principle of institutional balance should be interpreteddynamically. These officials work at the cutting edge of regulatory policy and hence are particularly concernedabout the loss of status and credibility of the Commission. A career in an independent European agency isviewed as a promising alternative. The discourse of both reformers and defenders of the status quo depends crucially on the concept ofinstitutional balance. I argue that this concept can be properly understood only in the context of the venerabletheory of mixed government. This suggests that the European Community is not so much sui generis as the latterdayversion of a pre-modern model of governance.ideas; national interest; common interest; institutions; Europeanization; Europeanization

Valuing Coupon Bond Linked to Variable Interest Rate

The paper analyses coupon bonds linked to variable interest rate in a contingent claim approach such that it can be decomposed in elementary options on interest rate and options to default. It is considered the case of continuous arithmetic average of interest rate in a simple capitalization to value the variable coupon paid by the bonds at maturity. The paper determines the expected interest rate on the bonds and the risk spread due to the default risk.Contingent claim, Asian option, Stochastic continuous process

International Economic Integration, National Autonomy, Transnational Democracy: An Impossible Trinity?

democracy; constitutional change; WTO; national interest; Nation-state; supranationalism

Tensor Berry connections and their topological invariants

The Berry connection plays a central role in our description of the geometric phase and topological phenomena. In condensed matter, it describes the parallel transport of Bloch states and acts as an effective "electromagnetic" vector potential defined in momentum space. Inspired by developments in mathematical physics, where higher-form (Kalb-Ramond) gauge fields were introduced, we hereby explore the existence of "tensor Berry connections" in quantum matter. Our approach consists in a general construction of effective gauge fields, which we ultimately relate to the components of Bloch states. We apply this formalism to various models of topological matter, and we investigate the topological invariants that result from generalized Berry connections. For instance, we introduce the 2D Zak phase of a tensor Berry connection, which we then relate to the more conventional first Chern number; we also reinterpret the winding number characterizing 3D topological insulators to a Dixmier-Douady invariant, which is associated with the curvature of a tensor connection. Besides, our approach identifies the Berry connection of tensor monopoles, which are found in 4D Weyl-type systems [Palumbo and Goldman, Phys. Rev. Lett. 121, 170401 (2018)]. Our work sheds light on the emergence of gauge fields in condensed-matter physics, with direct consequences on the search for novel topological states in solid-state and quantum-engineered systems.Comment: 10 pages, 1 table. Published versio